CloudBlue Commerce uses the TCP keep-alive mechanism for TCP connections between service controllers and between management node and CloudBlue Commerce agents. This mechanism has the IDLE, INTVL, and NPROBES parameters.
When the TCP keep-alive mechanism is turned on for TCP connection the operating system sets a timer for the connection. If the TCP connection is idle for IDLE seconds the operating system starts to send empty "ping” packets (one in INTVL seconds) to remote end. If no reply is received after the sending NPROBES packets, the connection is considered to be dead and is closed.
CloudBlue Commerce uses the following values of TCP keep-alive parameters:
- IDLE – 300 seconds (5 minutes)
- INTVL – 5 seconds
- NPROBES – 10 on Linux; 9 – on Windows
Thus, if your firewall handles the idle TCP connections in BackNet network, the firewall must not close the TCP connections which are in the idle state for less than 5 minutes.